Mobile station having waiting process with main power off

ABSTRACT

While main power in an automobile is off, a telematics station in the automobile intermittently runs to execute a process. The station has a first CPU in a wireless section for a wireless signal waiting process and a second CPU, having active and sleep modes, in a control section for resetting the first CPU. At resetting timing, if the first CPU is executing the process, it outputs a signal indicating that it is executing the process for the second CPU not to reset it. When the main power turns on, the second CPU determines that the signal is not outputted in order to reset the first CPU.

This is a Continuation of application Ser. No. 10/245,494 filed Sep. 18,2002. The entire disclosure of the prior application is herebyincorporated by reference in its entirety.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by referenceJapanese Patent Application Nos. 2001-287310 filed on Sep. 20, 2001,2001-287315 filed on Sep. 20, 2001, and 2002-198883 filed on Jul. 8,2002.

FIELD OF THE INVENTION

The present invention relates to a mobile station such as a telematicsstation in an automobile having a wireless signal waiting process whilemain power in the automobile is off. It is suitable for telematicsapplications that connect inside and outside of the automobile.

BACKGROUND OF THE INVENTION

Some mobile stations provided in moving objects, for instance intelematics, are required to run and remain in a wireless signal waitingprocess even while main power of the moving bodies is off. Here, thetelematics provides various services by the comprehensive utilization ofglobal positioning system (GPS), the Internet, the mobile station andothers. For instance, when an automobile or a ship is stolen, a serverstation determines the location of the stolen automobile or ship througha procedure of sending a command to the stolen automobile or ship thatshould obtain its own location information by using the GPS to return itto the server station.

When it is difficult for a car owner to find out his own car in premisessuch as a large parking lot, the owner can easily know the car locationthrough a procedure of calling the server station and having the serverstation send to the car a command that the car should honk a horn orblink a headlight on and off.

When an airbag is expanded in a car, a telematics station in the carthat has detected the expansion automatically sends out its locationinformation along with the information regarding the airbag expansion tothe server station. The service station contacts the driver in the car,following which the server station informs the police or an insurancecompany if emergency such as a traffic accident occurs. Thus, a promptaction can be possible to a trouble such as the accident.

The other services such as remote door lock/unlock, car stereo andhands-free phone cooperative system, and e-mail service have beenproposed.

In order to realize the above telematics services, even if the mainpower of the moving object is off, the mobile station in the movingobject must continue to run and remain in a wireless signal waitingprocess to be ready for receiving a command by a remote access,obtaining present location information, and transmitting a message.

The telematics station, in general, has a CPU for the wireless signalwaiting process or the receiving process. In the case, it is conceivablethat the CPU intermittently executes the wireless signal waiting processto save power consumption. The above CPU is reset, typically forsecuring reliable operation, at timing when main power turns on. If theCPU is reset when the CPU is executing the wireless signal waitingprocess or the receiving process, the process must be interrupted.

Moreover, for instance in the automobile, when an engine starts alongwith the main power turning on, battery voltage rapidly fluctuates andthe reset may not be always successful. Furthermore, quick repeating ofthe main power ON/OFF may result in failure of reset procedure. FIG. 6shows relation between wireless power voltage in a telematics stationand a reset signal (S-rst) in a case that main power ON occurs shortlyafter main power OFF. Here, the reset signal is generated by detectingpower ON. When a period from OFF to ON of the main power becomes tooshort, the voltage just before ON insufficiently reduces. Accordingly,the main power ON is not properly detected to result in failure ofgenerating the reset signal.

SUMMARY OF THE INVENTION

A first object of the present invention is to provide a mobile stationcapable of continuing to execute the process such as a wireless signalwaiting process or a receiving process without interruption. A secondobject of the present invention is to provide a mobile station capableof reliably resetting a CPU while main power of a moving object turnson.

To achieve above objects, a mobile station, which intermittently runs toexecute the wireless signal waiting process even when the main power ofthe moving object turns off, has a first CPU for the wireless signalwaiting process and a reset method for resetting the first CPU. Here,the reset method does not reset the first CPU when the first CPU isexecuting the wireless signal waiting process.

Moreover, the above reset method is replaced with a second CPUcommunicating with the above first CPU. The first CPU outputs to thesecond CPU a signal indicating that it is executing the wireless signalwaiting process. When the main power turns on, the second CPU resets thefirst CPU after determining that the signal is not outputted. Here, thereset is executed through communication between two CPUs, so thatfailure of the reset is prevented when the main power turns on.

Furthermore, to save the power consumption of the mobile station, thesecond CPU has sleep and active modes. While the main power is off, thesecond CPU does not shift from the sleep mode to the active mode untilit receives, from the first CPU, a signal indicating that the first CPUhas detected wireless reception.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription made with reference to the accompanying drawings. In thedrawings:

FIG. 1 is a block diagram illustrating a structure of a telematicsstation according to an embodiment of the present invention;

FIG. 2 is a flow diagram illustrating a procedure of a first CPU in awireless section (CPU-wl) with an ignition switch OFF according to theembodiment;

FIG. 3 is a flow diagram illustrating a procedure of a second CPU in acontrol section (CPU-cl) in an active mode according to the embodiment;

FIG. 4 is a diagram illustrating ON/OFF timing of a power request signal(S-prq) and a power control signal (S-pcl) in steps 530 and 531 shown inFIG. 3;

FIG. 5 is a diagram illustrating timing of a reset signal (S-rst) and apower control signal (S-pcl) in steps 522˜524 shown in FIG. 3; and

FIG. 6 is a diagram illustrating time-series behavior of wireless powervoltage with the ignition switch ON/OFF.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a telematics station includes a wireless section 1and a control section 2.

The wireless section 1 includes a CPU as the first CPU (CPU-wl) 101which executes a wireless signal waiting process, a receiving process,and a wireless communicating process, a phone module 102, a globalpositioning system (GPS) receiver 103, a real time clock (RTC) 104, apower-on reset circuit 105, an OR gate 106, a GPS receiver switch 107,and a phone module switch 108.

The CPU-wl 101 sends the phone module 102 a transmission signal for anantenna 110 to transmit a wireless signal, and receives a receptionsignal through the phone module 102 from the antenna 110. Also theCPU-wl 101 obtains location information from the GPS receiver 103connected with an antenna 109. Moreover, the CPU-wl 101 controls ON/OFFof the GPS receiver switch 107 used for a power supply to the GPSreceiver 103 and the phone module switch 108 used for power supply tothe phone module 102.

The RTC 104 possesses a timing counter (not shown) and shifts a powerrequest signal (S-prq) to ON (alarm outset), as described later, whenthe timing counter is incremented to preset time. The RTC 104 shifts theS-prq to OFF (alarm set) when the timing counter is reset by the CPU-wl101. Here, the ON of S-prq means that voltage is at high level while theOFF mode of S-prq means that voltage is at low level.

The power-on reset circuit 105 outputs a reset signal (S-rst) to theCPU-wl 101 for power-on reset when power is supplied.

The control section 2 includes a CPU as the second CPU (CPU-cl) 201 fora reset method, a power circuit 202, a wireless power circuit 203, andan OR gate 204. The control section 2 also includes an echo canceller(not shown) which outputs voice to an external voice output device (notshown) by the control of the CPU-cl 201. The CPU-cl 201 receives powerfrom the power circuit 202 and controls the wireless power circuit 203through the OR gate 204. The power circuit 202 receives power from anexternal battery power source.

The CPU-cl 201 possesses interfaces with in-vehicle local area network(LAN) and with user input devices such as a manipulation button, and aninput line through which ON/OFF of an ignition (IG) switch is detected.

The CPU-cl 201 communicates with automobile components of doors, a horn,lamps, airbags, an air conditioner, an audio unit, and others throughthe in-vehicle LAN. For instance, the CPU-cl 201, through the in-vehicleLAN, detects components' situations such as airbag's expansion andcontrols components' behavior such as door's switching.

A connecter 3 connects the wireless section 1 and the control section 2.Through the connector 3, a power supply line 301 from the power circuit202, a power supply line 302 from the wireless power circuit 203, aS-prq line 303, a reset control line 304, and a serial communicationline 305 carry signals between the wireless section 1 and the controlsection 2.

The RTC 104 in the wireless section 1 is continuously supplied withpower through the power supply line 301. The CPU-wl 101 and the power-onreset circuit 105 are supplied with power through the power supply line302.

When the IG is OFF, the CPU-cl 201 remains in a sleep mode until itreceives an external wake-up signal. In the sleep mode of the CPU-cl201, the CPU-wl 101 behaves as described later. When the IG is OFF, theRTC 104 constantly receiving the power supply sends out the S-prq as ONthrough the S-prq line 303 to the wireless power circuit 203 as thetiming counter expires every fifteen minutes.

As the wireless power circuit 203 detects the S-prq as ON, it supplies,with an internal switch ON, the wireless section 1 with the powerthrough the power supply line 302. Thus the power-on reset circuit 105starts to send out a S-rst through the OR gate 106 to the CPU-wl 101.

The CPU-wl 101 starts by the power supply through the power supply line302 from the wireless power circuit 203 to reset by receiving the S-rstthrough the OR gate 106 from the power-on reset circuit 105. The CPU-wl101 that has been reset immediately controls the phone module switch 108to have the phone module 102 supplied with the power.

Referring to FIG. 2, a procedure of the CPU-wl 101 following the startis explained.

At first, the CPU-wl 101 is reset following the start to execute awireless signal waiting process. At step 501, it sends out a wirelesssignal to a neighboring base station through the phone module 102(location registration), following which at step 502 it determineswhether it has received an incoming call. At step 502, the receivingprocess is executed instead of the wireless signal waiting process.Here, presence of reception may be determined in presence of a pluralityof incoming calls. For instance, the CPU-wl 101 determines the presenceof reception by detecting two time incoming calls a series of call-cutoff-call within a minute, so that it becomes easier to recognize whetherthe call should be from a telematics server station or from the others.

As the other instance, the presence of reception may be determined byreceiving a caller ID in the incoming call or a predetermined message ofa short message such as an e-mail, which also enables to recognizewhether the call should be from the telematics server station or from abase station. Here, when received data are specific to a telephonenetwork such as exchanged control information and are determined not torequire the control section 2 to execute them by observing the contentsof the received caller ID or the short message, the CPU-wl 101 does notsend out a receiving signal (S-rcv) to the CPU-cl 201 even though it hasreceived the data (not shown in FIG. 2). Accordingly, the CPU-cl 201remains in the sleep mode though the CPU-wl 101 is executing thewireless communicating process.

When absence of the reception is determined, the procedure proceeds tostep 503 to determine time-out which indicates that it has passed apredetermined period from the time when the location registration isdone. Here, when the procedure proceeds to step 503 from step 502, thewireless signal waiting process is substituted for the receiving processat step 502. The predetermined period to determine the time-out is setto, for instance, 30 seconds. Here, when the time-out is not determined,the procedure returns to step 502 to repeat steps 502 and 503 until thetime-out is determined or the presence of the reception is determined.Contrary, when the time-out is determined, the procedure proceeds tostep 504.

At step 504, an alarm of the RTC 104 is set, and then at step 505 theS-prq from the RTC 104 is set to OFF and the wireless signal waitingprocess ends. Hereby, with the stop of the power supply from thewireless power supply circuit 203, the CPU-wl 101 and the phone module102 stop their operations. The above series of the steps are resumed byan outset of the alarm of the RTC 104 and are repeated periodically orintermittently as long as the IG remains in OFF. In the above case, theCPU-wl 101 is executing the wireless signal waiting process, thereceiving process, and the wireless communicating process which isexecuted only by the CPU-wl 101 without the CPU-cl 201 which remains inthe sleep mode. Here, the CPU-wl 101 continues to have a clear-to-send(CTS) signal of a serial communication line 305 set to HIGH. Also, theCPU-wl 101 outputs data indicating that each communication is processingthrough a data line of the serial communication line 305. Pairs of theCTS signal and each data indicate signals of the wireless signal waitingprocess, the receiving process, and the wireless communicating process.

When the presence of the reception is determined at step 502, theprocedure proceeds to step 510 and the CPU-wl 101 sends out a S-rcvthrough the serial communication line 305 to the CPU-cl 201. Here, theS-rcv is different from a receiving-process signal. The CPU-cl 201shifts to an active mode from the sleep mode by detecting the S-rcv andsends out the CPU-wl 101 a command that the S-prq should be set to OFFthrough the serial communication line 305 in order to control thewireless power circuit 203 by itself. At step 511, the CPU-wl 101 thathas received the command controls the RTC 104 to shift the S-prq to OFF,following which the CPU-wl 101 executes step 512 called a serviceprocess. The receiving process thus ends. In addition, the serviceprocess includes executing communication after the reception of theincoming call, so that the service process includes the wirelesscommunicating process.

The service process is executed by collaboration between the wirelesssection 1 and the control section 2 to realize various kinds oftelematics applications as described above. An instance that starts theservice process through the reception of the incoming call is aprocedure for a stolen car. The car owner who has recognized that thecar is stolen notifies a service agency of the fact, following which theservice agency sends out to the stolen car a signal from a server of theservice agency. If the signal is, for instance, that it requires presentlocation information of the car, the wireless section 101 of thetelematics station of the stolen car that has received the signal entersthe service process through steps 510 and 511 as described above. Here,the CPU-wl 101 has the GPS receiver switch 107 set ON to obtain thelocation information through the GPS receiver 103. Then it returns theobtained location information to the server through the phone module102, which procedure reveals the present location of the stolen car.

When it is difficult for a car owner to find out his own car in premisessuch as a large parking lot which is still narrower than the aboveinstance, the owner may choose the following service. As soon as hecontacts a server station by a cell phone or others to carry out apredetermined procedure, the server station sends out the command signalthat has the car honk a horn or blink a headlight on and off. Thewireless section 1 of the car's telematics station that has received thecommand signal conveys the command to the control section 2. The controlsection 2 controls the horn or the headlight through the in-vehicle LAN.Thus, people including the owner in the vicinity of the car is enabledto detect the car location.

In addition, when car doors are locked with a door key inside or it isimpossible for lock/unlock of the doors to be operated in a normalmanner, the car owner may choose the following service. As soon as hecontacts the server station by a cell phone or others, the serverstation sends out the command signal that instruct unlock or lock of thedoors. The car's telematics station controls the lock/unlock of thedoors through the in-vehicle LAN.

Incidentally, in the above service processes, if the locationinformation is additionally needed, the CPU-wl 101 has the GPS receiverswitch 107 ON to obtain the location information through the GPSreceiver 103.

When the service process is completed, the CPU-wl 101 resets the counterof the RTC 104 at step 513. Then, the CPU-cl 201 shifts the S-pcl toOFF, so that the CPU-wl 101 stops along with the phone module 102. Theforegoing is the major procedure of the CPU-wl 101 while IG is OFF.

As explained above, the period that the CPU-wl 101 is detecting thereception of the incoming call at step 502 and also the period fromdetermining the reception at step 502 to entering the service process at512 are defined as staying in the receiving process. While the CPU-wl101 is detecting the reception, it sends out the receiving-processsignal to the CPU-cl 201 through the serial communication line 305 alongwith outputting a reception ring to the CPU-cl 201 through a voicesignal line (not shown).

As long as the CPU-cl 201 is in the active mode regardless of ON/OFF ofthe IG, the CPU-wl 101 stays in the wireless signal waiting processuntil it shifts to other processes such as the receiving process, thewireless communicating process and the service process.

The procedure of the CPU-cl 201 in the active mode is explained asfollows. The CPU-cl 201 enters the active mode through a plurality oftriggers. The first trigger is receiving the S-rcv from the CPU-wl 101as described above. The other is receiving an IG ON or an external inputsignal from the in-vehicle LAN, user interfaces and others. An instanceof the input from the in-vehicle LAN is that the in-vehicle LANautomatically detects and notifies the telematics station inside the carwhen the forced power is applied to the car body or the door window isbroken. Here, the telematics station sends out an alarm message to theserver station according to the notification from the in-vehicle LAN,following which the server station takes action such as informing thecar owner or the police of the fact.

Referring to a flow diagram in FIG. 3, the procedure of the CPU-cl 201in the active mode is explained. The procedure is divided into two kindsdepending on the cases that the mode is changed by receiving the S-rcvor not.

As the CPU-cl 201 shifts to the active mode, the next procedure is thatthe CPU-wl 101 should be reset. Here, at step 520, whether the shift isdone by receiving the S-rcv is determined. When the shift is determinedto be by receiving the S-rcv, the procedure proceeds to step 530. TheS-pcl from the CPU-cl 201 is shifted to ON and sent to the wirelesspower circuit 203 through the OR gate 204. Here, ON of the S-pcl meansthe voltage of the signal is at high level and OFF of the S-pcl meansthe voltage of the signal is at low level.

Next at step 531, the CPU-cl 201 sends out the command that the S-prqfrom the RTC 104 should be set to OFF through the serial communicationline 305. FIG. 4 shows timing of the S-prq ON→OFF and the S-pcl OFF→ONin the procedure at steps 530 and 531. The control role of the wirelesspower circuit 203 is transferred from the RTC 104 to the CPU-cl 201through the above procedure. However, as shown in FIG. 4, since theS-pcl ON or the S-prq ON from at least either of the CPU-cl 201 or theRTC 104 is being sent between step 530 and step 531, the wireless powercircuit remains ON by a function of the OR gate 204. Therefore thepower-on reset circuit 105 does not send out the S-rst, so that theCPU-wl 101 is never reset.

When the shift is determined to be not by receiving the S-rcv at step520, namely, the shift is by receiving an IG ON or an external inputsignal from the in-vehicle LAN, user interfaces and the others, theprocedure proceeds to step 521. At step 521, whether the CPU-wl 101 isat least in any process of the wireless signal waiting, the reception orthe wireless communicating is determined by the CTS signal from theCPU-wl 101. If the determination is YES, the procedure proceeds to step530 and the control role of the wireless power circuit 203 istransferred from the RTC 104 to the CPU-cl 201 without the CPU-wl 102being reset, as described above, at steps 530 and 531. Here, the abovecase is, for instance, that the CPU-wl 101 is executing any of the steps501→503 when the CPU-cl 201 shifts to active mode due to the IG ON.

In addition, as the CPU-cl 201 shifts to the active mode during thereceiving process, the CPU-cl 201 receives, from the CPU-wl 101, theS-rcv and the reception ring signal through the voice signal line (notshown) and outputs the reception ring to an external voice output deviceby controlling an echo canceller. Thus, the user of the telematicsstation recognizes it and is enabled to manually receive the call fromthe outside.

At step 521, when the determination is NO, the procedure proceeds tostep 522. At step 522, the CPU-cl 201 sets the S-rst to LOW (S-rstassert) to send out to the CPU-wl 101 through the reset control line 304and the OR gate 106. Then, at step 523, the CPU-cl 201 sets the S-pcl toON to send out to the wireless power circuit 203 through the OR gate204. Thus, the wireless power circuit 203 turns on and the CPU-wl 101starts. Here, the S-rst from the reset line 304 is at low level.Accordingly, the CPU-wl 101 executes the reset procedure and controlsthe phone module switch 108 to have the phone module 102 supplied withthe power. Continuously, the procedure proceeds to step 524 and theCPU-cl 201 sets the S-rst to HIGH (S-rst negate) after the interval of apredetermined period. FIG. 5 shows timing of the S-rst and the S-pcl inthe procedure at steps 522˜524. When step 524 or step 531 is completed,the procedure proceeds to step 525 to start the service process.

Though the service process is explained above, instances of the serviceprocesses during the IG ON are an airbag expansion automatic alert, carstereo and hands-free phone cooperative system, e-mail service andothers.

In the airbag expansion automatic alert, when the airbag is expanded ina car, the fact is reported to the telematics station through thein-vehicle LAN. The telematics station that has been reported obtainslocation information through the GPS receiver 103 to send it out to theservice station along with the information regarding the airbagexpansion through the phone module 102. The service station contacts thedriver in the car through telephone, following which it informs thepolice and an insurance company or calls an ambulance if the driver doesnot reply or the driver tells emergency such as an accident occurs.

In the car stereo and hands-free phone cooperative system, when thedriver calls without holding the telephone, he can hear the receivingvoice through the car stereo speaker. Here, when the phone module 102 ofthe telematics station is used for call, the control section 2 controlsthe car stereo through the in-vehicle LAN to output the voice from thecar stereo speaker.

In the e-mail service, the phone module 102 connects with an Internetprovider by manipulating a button of the telematics station or acomputer connected to the in-vehicle LAN, so that the e-mail is receivedor transmitted. Here, the telematics station may have its own display toshow the received e-mail or may convert the e-mail from text to voice tohave the car stereo speaker read it through the in-vehicle LAN. Inaddition, the transmission message may be input through the manipulationbutton or data stored in the computer may be directly sent through thein-vehicle LAN.

After the service process is completed, the procedure proceeds to step526 and whether the IG is ON/OFF is determined. If the IG is ON, theprocedure returns to step 525. If the IG is OFF, the procedure proceedsto step 527 and the CPU-cl 201 sets the S-pcl, which has been sent tothe wireless power circuit 203 through the RTC 104, to OFF to stop thepower supply to the CPU-wl 101 and the others. Then, the procedureproceeds to step 528 and the CPU-cl 201 shits itself to the sleep modeand completes the process.

In the above procedure, with the IG OFF, the CPU-wl 101 starts at aninterval of 15 minutes except for a specific command being generated andthe CPU-cl 201 returns to the sleep mode, so that power consumption canbe reduced.

Moreover, since the CPU-cl 201 sends out the S-rst when the IG turns on,the CPU-wl 101 is reliably reset even if the power-on reset circuit 105does not work properly.

However, if the IG turns on while the CPU-wl 101 is in the process ofwireless signal waiting, receiving, or wireless communicating, theCPU-cl 201 does not send out the S-rst and the power-on reset circuit105 also does not send out the S-rst by the procedure of S-pcl ON→S-prqOFF as described in steps 530 and 531. Thus, the CPU-wl 101 does notstop due to the reset, so that the process of wireless signal waiting,receiving, or wireless communicating is prevented from beinginterrupted.

The above embodiment may be modified as follows. In the aboveembodiment, the phone module switch 108 is used for the CPU-wl 101 tocontrol the power supply to the phone module 102. Meanwhile, voltagechange generated by rapid switching ON/OFF of the phone module switch108 can be used as a transmission signal when a digital communicationmethod is substituted for a phone. The substitution consumes less powerthan the procedure where the transmission signal is sent through thephone module 102 from the CPU-wl 101 with the phone module switch 108being constantly ON.

In addition, the IG ON/OFF may be inputted to the CPU-cl 201 not throughthe dedicated line different from the in-vehicle LAN as shown in FIG. 1,but through the in-vehicle LAN.

In addition, the period from the counter reset of the RTC 104 to theexpiration may be changed from 15 minutes to any other minutes.

In addition, though the above telematics station is divided into thewireless section 1 and the control section 2, it may not be divided.

In addition, though the above telematics station has the CPU-wl 101 andthe CPU-cl 201, two CPUs are not mandatory for executing functions andonly one CPU may execute all functions.

In addition, though the CPU-cl 201 operates in two kinds of the sleepmode and the active mode, it may constantly operate only in the activemode.

1. An emergency report system for a vehicle, the system comprising: awireless section that informs an emergency report center by transmittingdata, when an airbag of the vehicle is expanded; a reset section thatresets a CPU of the wireless section when an ignition switch of thevehicle is turned on; a determination section that determines whether ornot the wireless section executes one process of a wireless signalwaiting process and a wireless communicating process when the ignitionswitch is turned on; a reset prohibiting section that prohibits thereset section from resetting the CPU when the wireless section isdetermined to execute the one process.
 2. The emergency report system ofclaim 1, further comprising: a control section coupled with the wirelesssection via a connector to receive (i) a reset signal for detecting thatthe ignition switch is turned on and (ii) an airbag-expansion signal fordetecting that the airbag is expanded, and control the reset section toreset the CPU of the wireless section, via the connector.